how to detect memory leak in java

A memory leak is an object or variable that is no longer being used and is always occupied in memory. However, there is a garbage collection mechanism in Java that can automatically purge objects that are no longer in use from memory.Even so, there is a case of memory leaks

Write NIO programs often use Bytebuffer to read or write data, then use bytebuffer.allocate (capability) or bytebuffer.alloctedirect (capability) To allocate the cache? The first is to allocate JVM heap memory, which belongs to the GC jurisdiction, which is relatively slow due to the need for copying, and the second is to allocate OS local memory, which is not in GC jurisdiction, and is relatively fast beca

string can be said to be one of the most common Java types, but I've recently heard JDK6 inside String.substring There is a memory leak bug, gang stunned! Let's see what the situation is. This is the code that can cause the exception in thread "main" Java.lang.OutOfMemoryError:Java Heap space: publicclasstestgc{privatestringlargestring= Newstring (newbyte[100000

RefWatcher monitoring Fragment:Publicabstract class basefragment extends Fragment { @Override public void ondestroy{ Super. OnDestroy(); refwatcher refwatcher = exampleapplication. Getrefwatcher(getactivity()); refwatcher. Watch(this); }}Working mechanism RefWatcher.watch()Create a keyedweakreference to the object to be monitored. Then the background thread checks if the reference is cleared, and if not, the GC is called. If the reference is still not cleared, dump the heap

, so its life cycle is synchronized with the person, and the class object corresponding to the person class is resident in memory in case the person class is not unloaded until the program finishes running. -As a result, the object objects referenced by obj, once created, will also reside in memory until the end of the run. -4: Release references to useless objects as early as possible the5: Avoid creating

Yes. The reason Java causes memory leaks is clear: a long lifecycle object holds a reference to a short lifecycle object and is likely to have a memory leak, although the short lifecycle object is no longer needed, but because the long lifecycle object holds its reference and cannot be reclaimed, this is the scenario w

(); }} class Mymemory{public MyMemory () {}///The objects are stored in Heap public void Heapleaktest () {list4. Test ResultsHeap OverflowException in thread "main" Java.lang.OutOfMemoryError:Java heap spaceAt Com.dangdang.memoryleak$mymemory.heapleaktest (memoryleak.java:27)At Com.dangdang.MemoryLeak.main (memoryleak.java:12)Stack OverflowException in thread "main" Java.lang.StackOverflowErrorAt Com.dangdang.memoryleak$mymemory.stackleaktest (memoryleak.java:34)At Com.dangdan

Package com.ckw.mianshi;/** * Test memory leaks * Several events in Java that cause memory leaks: * A reference to an object that is held in a container such as 1.hashmap,verctor, although the object is already set to NULL, a memory leak * 2 will still occur. The use of the

.... ..... ....... ..............................Snapshot resolved.Started HTTP server on port 7000Server is ready. Dump file created Thu Mar 16:45:06 CST 2015 Snapshot Read, resolving ... Resolving 264282 objects ... Chasing references, expect, dots ..... ..... ..... ....... ......................... Eliminating duplicate references .... ..... ....... .............................. Snapshot resolved. Started HTTP server on port 7000 Server is ready. 3. The address bar input ip

, the next is to open the Code project for White-box transformation, the corresponding code optimization (not within the scope of this article.) Some of the PID inconsistencies in the diagram are not tangled, some of the system restarted again.For more content please visit the starting blog http://jenwang.meFurther communication:-Email:[email protected]-For some topics of this blog interested in, hope to further exchange, please add QQ Group: 2825967-more technical exchange sharing in the Circle

An important advantage of Java is the automatic management of memory recycling through the garbage collector (garbage COLLECTION,GC), where programmers do not need to invoke functions to free up memory. As a result, many programmers think that Java does not have a memory

does not release the memory in the destructor, so a memory leak occurs only once.4. An implicit memory leak. The program keeps allocating memory while it is running, but it does not release m